Temperature dependence of resistivity at the transition to a charge-density state in rare-earth tritellurides

Abstract:

The observed jump of resistivity at the partial charge-density state (CDW) transition in rare-earth tritellurides is less than 20%, although the major part of the Fermi surface become gapped, as seen from ARPES. Previously this observation was explained by suggesting an extremely slow increase of the CDW energy gap below the transition temperature in these compounds. Here we show that this weak change of resistivity at the CDW transition is a general phenomenon and can be explained even for the mean-field temperature dependence of CDW energy gap. The resistivity jump at the CDW transition is weak because the decrease of the density of conducting electrons at the Fermi level is almost compensated by the decrease of electron scattering rate. The calculated temperature dependence of resistivity is in a good agreement without any fitting parameters with available experimental data on three different rare-earth tritelluride compounds.